I. Field of the Invention
This invention relates in general to high temperature rechargeable lithium electrochemical cells and in particular to a high temperature rechargeable solid state lithium electrochemical cell operable at temperatures of about 300.degree. C. to about 400.degree. C.
II. Description of the Prior Art
High temperature rechargeable molten salt lithium electrochemical cells are required for electric propulsion, load leveling and pulse power applications. Amongst the many molten salt electrochemical systems that have been studied over the past many years, the lithium alloy/metal sulfide cells have shown considerable promise for these applications. These cells have used a lithium alloy (LiAl) as the anode, an electrolyte including a molten mixture of lithium halide, metal and alkali halides and a transition metal sulfide (FeS.sub.2, CoS.sub.2, TiS.sub.2) as the cathode. The use of molten electrolytes, however, has introduced problems of sealing the cells as well as causing corrosion of cell components at the operating temperatures of about 400.degree. C. to 500.degree. C.